ST. PETERSBURG, Fla. (AP) — Jonathan Papelbon bailed Boston out of an eighth-inning jam and Jason Bay, J.D. Drew and Kevin Youkilis homered Tuesday night to help the Red Sox beat the Tampa Bay Rays 8-4 in the opener of a series crucial to the AL wild-card race.

Papelbon entered with two runs in and the bases loaded with no outs and shut down the AL champions in the eighth with help from a diving catch by center fielder Jacoby Ellsbury, who snared Jason Bartlett’s sinking liner before scrambling to his feet to keep a runner from tagging up at third.

Papelbon, who struck out B.J. Upton for the first out, got Carl Crawford to foul out to end the inning. The right-hander pitched a perfect ninth for his 33rd save, fifth of more than one inning.

The victory was the 11th in 14 games for Boston, which got a rare win at Tropicana Field to drop Tampa Bay a season-high six games behind the wild-card leaders.

Just as discouraging for the Rays, who also trail Texas in the wild-card standings, was the announced crowd of 17,692 – less than half the capacity at Tropicana Field and 11,755 less than the teams averaged for six other meetings in the domed stadium this season.

The Red Sox remained 6½ games behind the first-place New York Yankees in the AL East.

Boston lost to the Rays in a seven-game AL championship series last year.

Jon Lester (11-7) allowed two runs and seven hits, walked one and struck out nine in six innings. He gave up an RBI single and solo homer to Carlos Pena, who hit his AL-leading 39th leading off the fourth.

Bay hit his 30th homer, a solo shot in the fourth off Andy Sonnanstine (6-8), who returned from a two-month stint in the minor leagues to – at least for the moment – fill the opening in Tampa Bay’s rotation created by the trade that sent Scott Kazmir to the Los Angeles Angels.

Drew hit a two-run homer off the Rays starter in the fourth. Youkilis had a sacrifice fly off Sonnanstine and hit his 23rd homer off Dan Wheeler to increase Boston’s lead to 7-2 in the eighth.

Billy Wagner pitched a perfect seventh in his second appearance for the Red Sox since being acquired from the New York Mets last week, but the Rays made it interesting in the eighth against Hideki Okajima.

All five batters Okajima faced reached base, with Pat Burrell and Dioner Navarro delivering RBI singles to trim Tampa Bay’s deficit to 7-4. Red Sox manager Terry Francona then turned to Papelbon an inning earlier than usual.

Boston won for just the second time in seven games at Tropicana Field this year. The Red Sox are 3-13 in the Rays’ ballpark over the past two regular seasons.

Sonnanstine made his first big league start since beating Philadelphia on June 25. He had the highest ERA (6.61) in the majors when he was demoted to the minors two days later, and was 1-7 with an 8.22 ERA in nine road starts.

The right-hander had been much sharper at home (5-0, 4.54 ERA) before Tuesday night, although a pair of fielding errors – one by second baseman Akinori Iwamura, and the other by first baseman Pena – set up a pair of Boston runs.

Ellsbury followed Iwamura’s second-inning miscue with an RBI single that made it 1-1. After Drew’s homer put Boston up 3-1, the Red Sox loaded the bases in the fourth on Pena’s error, a walk and a single before Youkilis drove in the third run of the inning with a sacrifice fly.

Bay’s homer, giving him at least 30 in a season for the fourth time, and Mike Lowell’s double finished Sonnanstine, who allowed five runs – three earned – and eight hits in four-plus innings.

Ellsbury’s RBI triple in the ninth made it 8-4.

NOTES: Lester struck out the side in the second, hiking his season total to 191 – a record for a Red Sox left-hander. He finished with 196. Bruce Hurst fanned 190 for Boston in 1987. … Pena has four homers in 26 career at-bats against Lester. … The Rays received minor league 2B Sean Rodriguez from the Angels, completing the trade for Kazmir. To make room on the 40-man roster, Triple-A Durham reliever Joe Nelson was designated for assignment. … Boston RHP Tim Wakefield had a light workout one day after receiving a cortisone shot for his ailing back. RHP Daisuke Matsuzaka (right shoulder) is scheduled to make his third minor league rehab start Friday for Triple-A Pawtucket.